Septic Systems

Safe treatment and disposal of all wastewater is necessary to protect the public health and the environment. Within the city limits of Great Falls, sewage is treated at the wastewater treatment plant before it is discharged to the river. Other municipalities in the county may also be on a public community wastewater system, such as lagoons which are regulated by the Montana Department of Environmental Quality.


View the updated Cascade County Regulations for Subsurface Wastewater Treatment Systems (PDF), effective July 5, 2014.

Homes or other structures that have individual on-site septic systems are regulated through a permitting process by our department. City-County Health Department also recognizes the importance of proper treatment and disposal of wastewater, so local and state regulations are followed to ensure safe disposal of sewage/wastewater. The basic principles include:

  • Construction
  • Design
  • Installation
  • Maintenance
  • Proper siting